The savings potential of presence detection (see also chapter „German standard DIN V 18599”) on the one hand depends on the degree of absence detection. Another factor, however, is the function of switching back on. It can be triggered automatically when detecting presence again, or manual switching on can be required. For the purpose of energetic lighting optimisation, these two factors should be considered in combination to a certain extent.
In many applications, the degree of absence detection essentially depends on the hold time which needs to pass after the last motion is detected before the light is switched off.